Fix clang compiler warnings about 'const'.  Suggested by Leonid Onokhov.
Fix clang compiler warnings about 'const'.  Suggested by Leonid Onokhov.


git-svn-id: 93cebb81a0f5cc00f31a7ad40d16024532691b70@866 a3683778-fedd-11de-87c3-653bb6514e15

yaroslav-tarasov/OpenShadingLanguage,sjparker/OpenShadingLanguage,imageworks/OpenShadingLanguage,lgritz/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,Anteru/OpenShadingLanguage,mcanthony/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,lgritz/OpenShadingLanguage,svenstaro/OpenShadingLanguage,svenstaro/OpenShadingLanguage,brechtvl/OpenShadingLanguage,lgritz/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,juvenal/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,Anteru/OpenShadingLanguage,brechtvl/OpenShadingLanguage,aconty/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,aconty/OpenShadingLanguage,juvenal/OpenShadingLanguage,aconty/OpenShadingLanguage,imageworks/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,mcanthony/OpenShadingLanguage,imageworks/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,juvenal/OpenShadingLanguage,rlmh/OpenShadingLanguage,mcanthony/OpenShadingLanguage,svenstaro/OpenShadingLanguage,gzorin/OpenShadingLanguage,gzorin/OpenShadingLanguage,brechtvl/OpenShadingLanguage,aconty/OpenShadingLanguage,lgritz/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,rlmh/OpenShadingLanguage,brechtvl/OpenShadingLanguage,juvenal/OpenShadingLanguage,rlmh/OpenShadingLanguage,svenstaro/OpenShadingLanguage,Anteru/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,aconty/OpenShadingLanguage,mcanthony/OpenShadingLanguage,brechtvl/OpenShadingLanguage,sjparker/OpenShadingLanguage,sjparker/OpenShadingLanguage,gzorin/OpenShadingLanguage,gzorin/OpenShadingLanguage,gzorin/OpenShadingLanguage,imageworks/OpenShadingLanguage,sjparker/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,imageworks/OpenShadingLanguage,lgritz/OpenShadingLanguage,rlmh/OpenShadingLanguage,Anteru/OpenShadingLanguage